In a prior art fluid machine, for example shown in Japanese (Non-examined) Patent Publication S63-96449, heat energy is collected by Rankine cycle, wherein a compressor is also used as an expansion device for converting the collected heat energy into mechanical rotational force.
The compressor sucks liquid-phase working fluid into a working chamber thereof and compresses the working fluid by decreasing the volume of the working chamber as a result of applying mechanical force from the outside, whereas the expansion device generates mechanical force by expanding the high pressure and superheated working fluid in the working chamber. As above, when the compressor is also used as the expansion device, the flow of the working fluid should be reversed.
In the above prior art technology, namely in a fluid machine having functions of an expansion and compressor device, an inlet port of the working fluid in an operation of the heat collecting cycle and an inlet port of the working fluid in an operation of the refrigerating cycle are located on the same side, and an outlet port of the working fluid in the operation of the heat collecting cycle and an outlet port of the working fluid in the operation of the refrigerating cycle are located on the same opposite side. Accordingly, the fluid machine of the above prior art is complicated in its construction and becomes larger in its size.
The applicant of the present invention proposed in its prior Japanese patent application No. 2003-19139 (which is also filed in USPTO and EPO, the filing numbers of which are not yet given) a new fluid machine, in which a pair of fluid ports is formed for the fluid machine and one of the ports is used as an inlet port for the heat collecting cycle and an outlet port for the refrigerating cycle, whereas the other port is likewise used as an outlet port for the heat collecting cycle and as an inlet port for the refrigerating cycle, so that the fluid machine would become simpler in its construction and smaller in its size. In the fluid machine of this prior patent application, an electric rotating device is operatively connected to an expansion-and-compressor device. As understood from this prior patent application, a rotational force is directly transmitted (without a speed increase or decrease gear) from the electric rotating device to the expansion-and-compressor device and vice versa.
A rotational speed at which the expansion device is operated with its maximum efficiency and a rotational speed at which the electric rotating device is operated with its highest efficiency are not always the same to each other. In view of this point, it is more preferable to operate the expansion device and the electric rotating device at different rotational speeds, at which those devices can be respectively operated with much higher efficiency.
In another prior art, as shown in US Patent Application Publication No. 2003/0115877 A1, an expansion device is operatively connected to an electric rotating machine via a power transmitting mechanism. It is, however, not disclosed in this prior art how to construct the expansion device, the electric rotating machine and the power transmitting mechanism to achieve a fluid machine of a simpler construction and small in size.